Table 94 16-bit network number subnet planning, Configuring ip addresses – ZyXEL Communications ZyXEL Dimension ES-2108 User Manual
Page 269
ES-2108 Series User’s Guide
Appendix B IP Addresses and Subnetting
269
The following table is a summary for subnet planning on a network with a 16-bit network
number.
Configuring IP Addresses
Where you obtain your network number depends on your particular situation. If the ISP or
your network administrator assigns you a block of registered IP addresses, follow their
instructions in selecting the IP addresses and the subnet mask.
If the ISP did not explicitly give you an IP network number, then most likely you have a single
user account and the ISP will assign you a dynamic IP address when the connection is
established. If this is the case, it is recommended that you select a network number from
192.168.0.0 to 192.168.255.0. The Internet Assigned Number Authority (IANA) reserved this
block of addresses specifically for private use; please do not use any other number unless you
are told otherwise. You must also enable Network Address Translation (NAT) on the ES-
2108/ES-2108-G.
Once you have decided on the network number, pick an IP address for your ES-2108/ES-
2108-G that is easy to remember (for instance, 192.168.1.1) but make sure that no other device
on your network is using that IP address.
The subnet mask specifies the network number portion of an IP address. Your ES-2108/ES-
2108-G will compute the subnet mask automatically based on the IP address that you entered.
You don't need to change the subnet mask computed by the ES-2108/ES-2108-G unless you
are instructed to do otherwise.
Table 94 16-bit Network Number Subnet Planning
NO. “BORROWED”
HOST BITS
SUBNET MASK
NO. SUBNETS
NO. HOSTS PER
SUBNET
1
255.255.128.0 (/17)
2
32766
2
255.255.192.0 (/18)
4
16382
3
255.255.224.0 (/19)
8
8190
4
255.255.240.0 (/20)
16
4094
5
255.255.248.0 (/21)
32
2046
6
255.255.252.0 (/22)
64
1022
7
255.255.254.0 (/23)
128
510
8
255.255.255.0 (/24)
256
254
9
255.255.255.128 (/25)
512
126
10
255.255.255.192 (/26)
1024
62
11
255.255.255.224 (/27)
2048
30
12
255.255.255.240 (/28)
4096
14
13
255.255.255.248 (/29)
8192
6
14
255.255.255.252 (/30)
16384
2
15
255.255.255.254 (/31)
32768
1